Application of supercritical carbon dioxide fluid extraction technology in furfural production process

The supercritical carbon dioxide fluid extraction technology was used in the furfural production process by dehydration and cyclization of xylose. Under the conditions of feeding mass fraction 5.0% xylose 680 g and mass fraction 5.0% dilute sulfuric acid 6.8 g, with the flow rate of SC-CO2 extractant 0.10 g/s and reaction for 180 min. under 170°C, the conversion of xylose increased 2.4 percent point. The selectivity of furfural increased 29.8 percent point and the furfural yield increased 23.4 percent point, compared with that without using SC-CO2. Under experiment conditions with SC-CO2 as extractant, SC-CO2 temperature (35±1)°C, pressure (16±0.5) MPa, the optimum xylose dehydration and cyclization reaction temperature 180°C, the flow rate of SC-CO2 extractant 0.10 g/s, and reaction time 180 min, the furfural yield was up to 63.0%.